Dispenser and method for dispensing a product under pressure

ABSTRACT

A dispenser comprises a reservoir containing a pressurized product and the reservoir has an opening in which a valve is mounted. The valve comprises an closure element disposed within the reservoir. In response to an actuation of the dispenser, the closure element moves to an open position and allows the product to be dispensed under pressure from the reservoir through at least one outlet of the dispenser. When actuation of the dispenser ceases, the closure element returns to a closed position preventing flow communication between the outlet and the reservoir. The closure element moves to the closed position substantially by the pressure inside the reservoir acting on the closure element. The closure element is integral with a valve stem of the valve.

[0001] The present invention relates to a dispenser for the dispensingof a product under pressure, such as a liquid product, for example, thatcan be used in numerous applications such as cosmetics, food processing,and dermatopharmacology.

[0002] Conventional aerosol containers may comprise a reservoir, formedby a can, usually of metal or plastic, with a free edge defining anopening in which a valve may be mounted. The valve generally is mountedon a dome-like structure and is “crimped” or “rolled” onto the free edgeof the can. Inside the can is the product to be dispensed, whichgenerally is in liquid form, and a propellant gas, which may or may notbe mixed with the product to be dispensed.

[0003] The valve includes an essentially cylindrical valve body with aninlet orifice and an outlet orifice. Inside the valve body is anopening/closing member which may be in the form of a stem having onepart disposed inside the valve body while another part emerges from thevalve body. Mounted on the emerging part of the valve stem is anactuating member in the form of a pushbutton containing at least oneorifice through which the product can be released. The valve stemcontains an axial channel communicating, via at least one radialportion, with the interior of the valve body.

[0004] In one possible configuration, when the valve is closed, the openend of the radial portion of the channel is level with the inner annularedge of a seal mounted around the outlet orifice of the valve body. Theopening/closing member is constrained in this closed position by aspring inside the valve body. To dispense the product, the user appliespressure to a bearing surface of the pushbutton, which pressure issufficient to overcome the return force of the spring and depress thevalve stem until the radial portion or portions of the channel runningthrough the valve stem are no longer level with the seal. Thepressurized product inside the valve body then flows up inside the valvestem and is channelled toward the outlet orifice of the actuating membervia at least one passage connecting the outlet orifice with the valvestem. When the pressure on the bearing surface of the actuating memberis released, the spring returns the opening/closing member to the closedposition to cease the dispensing of the product.

[0005] Aside from the additional costs, the spring complicates theassembling of such a valve. Moreover, the material selected for thespring must be compatible with the composition to be dispensed. Thepresence of the spring also necessitates the use of a valve body to keepthe spring in engagement with the opening/closing member.

[0006] To alleviate the problems associated with a spring, one proposalhas been to use a valve with a valve body made of elastomeric material.The elasticity of the material forming the valve body is exploited toconstrain the opening/closing member toward the closed position. One ofthe problems with such an arrangement is the difficulty of materialincompatibility. Such incompatibility can arise in certain situationsbetween the elastomer of the valve body and the product to be dispensed.

[0007] U.S. Pat. No. 5,623,920 discloses an aerosol container having avalve mounted with axial mobility inside an external enclosure. Incertain embodiments, the return of the valve to the closed position maybe the result of a return force associated with a spring mounted betweenthe bottom of the container and the external enclosure, the valve stemhaving a fixed axial position relative to the container.

[0008] U.S. Pat. No. 4,852,807 discloses a neoteric aerosol valve inwhich the valve does not include a valve body. The valve stem is locatedin a structure, part of which forms a resilient diaphragm so as toreturn the valve to the closed position when the actuation isdiscontinued.

[0009] FR-A-1 379 202 discloses a valve device in which an elasticelement fixed to the container returns the valve to the closed positionwhen the actuation is discontinued.

[0010] U.S. Pat. No. 3,990,613 also discloses an aerosol containerfitted with a valve that comprises an elastic element to return thevalve to the closed position. Valve closure is the result of the contactbetween a seal (integral with the valve) and the inside wall of thecontainer.

[0011] U.S. Pat. No. 3,682,355 discloses an container with a pressureactuated valve which under the action of the pressure inside thecontainer returns it to the closed position when the actuation isdiscontinued. The valve includes a valve stem moved by a lever. A valvemember inside the container seals the container. The valve member iskept pressed against a seat by the action of the pressure inside thecontainer and is separated from the valve seat by the stem pressing onit when the lever is tilted. The valve member is not integral with thevalve stem. Such a device comprises several independent parts.Furthermore, the valve member and the stem are not integral and moverelative to one another, which results in a gap between these two partssuch that actuation does not result in an immediate opening of thevalve.

[0012] As embodied and broadly described herein, the invention includesa dispenser, which may be of the aerosol type. This dispenser mayoptionally solve some or all of the problems discussed above withreference to conventional dispensers.

[0013] In one optional aspect, the return to the closed position of avalve closure element, and its retention in the closed position, can bebrought about, at least partially, by the pressure inside the container.In one optional embodiment, the dispenser may lack a spring or any otherelastic return member associated with the valve. Optionally, the valvemay also lack a valve body.

[0014] It should be understood that the invention could be practicedwithout performing one or more of the optional aspects and/or advantagesdescribed herein. Certain other optional aspects of the invention willbecome apparent from the detailed description which follows.

[0015] According to an embodiment of the invention, a dispensercomprises a reservoir for containing a pressurized product, thereservoir defining an opening. The dispenser further includes a sealingmember positioned on the reservoir and a valve mounted in the opening ofthe reservoir. The valve includes a closure element disposed within thereservoir. The closure element is configured to move between a closedposition wherein the closure element engages the sealing member toprevent flow communication between an outlet of the dispenser and thereservoir and an open position wherein the outlet is in flowcommunication with the reservoir. The closure element is moved to theclosed position substantially by pressure inside the reservoir and ismoved to the open position in response to an actuation of the dispenser.

[0016] In another embodiment according to the invention, a dispenser fordispensing a product comprises a reservoir configured to contain aproduct under pressure. The dispenser further comprises a valve mountedon the reservoir. The valve includes a valve stem and a closure elementdisposed within the reservoir and integrally formed with the valve stem.The closure element is configured to be moved between a closed positionwherein flow communication between an outlet of the dispenser and thereservoir is prevented and an open position wherein the outlet is inflow communication with the reservoir. The closure element is moved tothe closed position substantially by the pressure in the reservoir.

[0017] In yet another embodiment according to the invention, a dispenserfor dispensing a product comprises a reservoir for containing a productunder pressure and a valve mounted on the reservoir. The valve includesa valve stem and a closure element disposed within the reservoir andfixed to the valve stem so as to prevent relative motion between theclosure element and the valve stem. The closure element is configured tomove between a closed position wherein flow communication between anoutlet of the dispenser and the reservoir is prevented and an openposition wherein the outlet is in flow communication with the reservoir.The closure element is moved to the closed position substantially by thepressure in the reservoir.

[0018] Optional embodiments may lack a valve spring, and optionally thevalve body, of prior dispensers. In addition, some optional embodimentsmay lack certain elastomeric materials which can cause problems ofcompatibility with certain products. Furthermore, the valve may berelatively easy to assemble. Also, the closure element on which thepressure acts may be either integral with the valve stem or fixed to thevalve stem so as to prevent relative motion with respect to the valvestem. This may allow for the immediate opening of the valve uponactuation of the dispenser, thereby producing a reliable device.

[0019] The closure element may be moved to the closed positionsubstantially by pressure inside the reservoir. The term “substantially”indicates that other forces tending to move the closure element towardthe closed position, such as a contributory action of a seal (typicallyan elastomeric seal) that may be disposed in the reservoir, arenegligible compared with that exerted by the pressure inside thecontainer. According to embodiments of the invention, the pressure inthe reservoir contributes to the movement of the closure element to theclosed position by more than 50%, preferably by more than 75%, and evenmore preferably by more than 90%.

[0020] The term “integral” as used herein to describe the relationshipbetween certain elements of the dispenser according to certain optionalembodiments of the invention indicates that the elements are formed as asingle, unitary structure.

[0021] A propellant may be used to pressurize the dispenser and mayinclude a liquefied or unliquefied gas. If a liquefied or unliquefiedgas is used, it may be generally lighter than the product to bedispensed, so that in order to use the dispenser with an actuationmechanism at the top of the dispenser, a dip tube may be connected tothe valve. For this purpose, the valve may have a valve body with aninlet orifice connected to the dip tube, and a free end of the dip tubesituated close to the bottom of the container. In the case of using thedispenser with an actuator at the bottom, such a dip tube and valve bodymight be provided. Alternatively, the propellant gas may be separatedfrom the product by a piston, or by a flexible-walled bag defining aninternal volume containing the product.

[0022] The portion of the closure element on which the pressure insidethe reservoir is exerted is advantageously integral only with the valvestem. In other words, the closure element may be free of any connectionother than its attachment to the valve stem. This arrangementfacilitates the fitting of the valve to the reservoir. Moreover, thepressure inside the reservoir for shutting the valve is less when thisportion is free than when it is fixed to other elements of thedispenser. It therefore may be possible not to have any type of elasticreturn for valve closure and essentially only the pressure inside thecontainer may be used for such closure.

[0023] Moreover, the closure element may comprise a valve stem able toslide in a leaktight manner in a passage formed in a seal situated inthe opening of the reservoir. The stem may contain an axial channel thatis in flow communication with at least one radial channel designed to beplaced in flow communication with the pressurized product inside thereservoir in response to actuation of the dispenser.

[0024] The closure element may be in the form of a base member formedcontinuously or discontinuously around a bottom portion of the valvestem disposed in the reservoir so as both to retain the valve on thedispenser and, where applicable, to create a seal. The base member maybe an annulus with an annular ring extending vertically from an edge ofthe annulus toward a top of the dispenser. Alternatively, the basemember may include a plurality of radially extending leg members. Thebase member may be inscribed in a circle whose cross-sectional area S₃is greater than the cross-sectional area S₂ of the valve stem. Becauseof a pressure gradient within the reservoir, the pressure at a face ofthe annular base member facing a bottom of the reservoir, and thus theforce exerted on that face, may be greater than the pressure at theopposite face of the annular base member facing a top of the reservoir,and thus the force exerted on the opposite face, (assuming the pressureinside the container to be greater than atmospheric pressure). There maybe thus a first force differential contributing to the return of theclosure element to the closed position.

[0025] In addition, and still assuming that the pressure inside thecontainer is greater than atmospheric pressure, the pressure at the endof the valve stem inside the container, and thus the force exerted onthe cross-sectional area S₂ at the end of the valve stem inside thecontainer, may be greater than the pressure at the end of the valve stemsituated outside the container, and thus the force exerted on thecross-sectional area S₂ of the end of the valve stem situated outsidethe container. There may be a second force differential that alsocontributes to the return of the closure element to the closed position.

[0026] The second force differential depends on the pressure gradientinside an axial channel passing through the valve stem. The averagepressure inside the axial channel may be a pressure whose value liessomewhere between atmospheric pressure and the pressure inside thereservoir. Whatever its value, the force differential may be such thatthe closure element is constrained to resume its closed position.

[0027] Inside the reservoir, the pressure may be such that, throughoutthe life of the product, the pressure may be at least greater thanatmospheric pressure. The pressure difference may be decided by suchfactors as, for example, the desired speed of closure and the desiredresistance to opening in order to minimize the risk of accidentalspraying. In practice, an excess of pressure also may be provided tocounterbalance other forces acting to move the closure element to theopen position, such as the friction between the outer surface of thevalve stem and the seal, as well as the weight of the valve stem and ofa pushbutton actuation mechanism, and other similar structuralcomponents of the dispenser, which are generally negligible.

[0028] In certain embodiments, actuation includes axially depressing thevalve stem. Alternatively, actuation may include tilting the valve stem.On its portion situated outside of the container, the valve stem mayinclude a stop mechanism that limits the axial depression of the valvestem toward a bottom of the reservoir in response to actuation. Thevalve preferably may be mounted in an opening defined by the reservoir.

[0029] In another embodiment of the dispenser according to theinvention, when the closure element is in a closed position, the openend of at least one radial channel in the valve stem is level with aninner annular edge of a sealing member, which may be disposed in anupper portion of the reservoir. An axial depression of the valve stem inresponse to actuation causes a displacement of the at least one radialchannel relative to the inner annular edge of the sealing member, whichplaces the outlet of the dispenser in flow communication with thereservoir via the radial and axial channels.

[0030] In yet another embodiment according to the invention, the openend of the at least one radial channel is level with an annular zonebounded by an annular ring, which, when the closure element is in aclosed position, engages in a leaktight manner against a surface of thesealing member. The axial depression or the tilting of the valve stem inresponse to actuation causes a disengagement of at least a portion ofthe annular ring relative to the surface of the sealing member to placethe outlet of the dispenser in flow communication with the reservoir viathe radial and axial channels.

[0031] Actuation of the dispenser may occur via an actuating mechanism,which may be in the form of a pushbutton, for example. The pushbuttonmay be mounted on the valve stem and define at least one outlet of thedispenser. The outlet may be formed in a nozzle, which may include swirlchannels. The outlet may be in flow communication with the axial channelof the valve stem.

[0032] The sealing member preferably defines a passage in which thevalve stem is slidably disposed. At least a portion of a surface of anedge bounding the passage defined by the sealing member may be coveredwith a coating, such as silicone or Teflon, to facilitate the axialsliding of the stem through the sealing member's passage.

[0033] The dispenser according to certain embodiments of the inventioncan be used for the pressurized packaging and dispensing of a cosmeticproduct, such as a hair product (styling lacquer, spray), care product,make-up product or personal hygiene product, for example. The reservoirmay contain the cosmetic product and a pressurized propellant.

[0034] Another optional aspect of the invention includes a method ofdispensing a product comprising providing a dispenser of one of thevarious types discussed above, actuating the dispenser to move theclosure element to the open position, dispensing a product underpressure from the dispenser in response to the actuating, ceasing theactuating, and moving the closure element to the closed positionsubstantially by the pressure in the reservoir. The moving the closureelement to the closed position may include moving the closure element bythe pressure on a face of the closure element facing a bottom of thereservoir. The actuating preferably includes one of axially depressingand tilting a valve stem of the valve. The actuating preferably causesimmediate movement of the closure element to the open position. Theactuating may include inverting the dispenser.

[0035] In another embodiment, the method includes dispensing the productby flowing the product through the outlet of the dispenser. Thedispensing may further include flowing the product through at least onechannel defined by the valve and in flow communication with the outlet.

[0036] In yet another embodiment, the method includes engaging theclosure element with a sealing member of the dispenser.

[0037] Aside from the structural and procedural arrangements set forthabove, the invention could include a number of other arrangements, suchas those explained hereinafter. It is to be understood that both theforegoing description and the following description are exemplary, andare intended to provide further explanation of the invention as claimed.

[0038] The accompanying drawings are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings,

[0039]FIG. 1 is a side cross-sectional view of a first embodiment of thedispenser according to the invention, adapted for head-down dispensing;

[0040]FIG. 2 is a view of the upper portion of the dispenser of FIG. 1showing the operation of the dispenser;

[0041]FIG. 3 is a perspective view of the closure element of the valveused in the dispenser of FIGS. 1 and 2; and

[0042]FIG. 4 is a perspective view of the closure element of the valvein accordance with a second embodiment of the invention.

[0043] Reference will now be made in detail to certain presentembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

[0044] The dispenser 1 illustrated in FIG. 1 comprises a cylindricalreservoir 2 of axis X. Reservoir 2 may be a can made of aluminum ortinplate, for example. One end of the can 2 is closed by a bottom 3.Inside the reservoir 2 is a product to be dispensed along with apropellant gas, such as butane, for example. The initial pressure insidethe reservoir may be on the order of a few bars. The end of thereservoir 2 opposite to the bottom 3 includes a rolled edge 4 definingan opening 5. A cap 6 containing a valve 7 is crimped onto the rollededge 4 of the reservoir 2. Inside the cap 6 is an annular sealing member8 whose outer edge is held between the rolled edge 4 and the cap 6supporting the valve 7, thereby ensuring sealed assembly of the cap 6relative to the reservoir 2. Inside a central passage 9 defined by aninner edge 10 of the annular sealing member 8 slides a valve stem 12.The valve stem 12 slides in a leaktight manner through the passage 9 inthe sealing member 8, and emerges on the outside of the cap 6 through anorifice lying over the passage 9 passing through the sealing member 8.

[0045] When it emerges from the reservoir 2, the valve stem 12 comprisesa portion 25 whose cross section is greater than that of the passage 9passing through the sealing member 8 in order to ensure that, before thecontainer is pressurized and before the pushbutton (to be discussedlater) is fitted on the valve, the valve stem 12 cannot fall into thereservoir 2.

[0046] The valve stem 12 defines an axial channel 13 ending in thevicinity of a lower end of the valve stem 12 disposed within thereservoir 2. A channel 14 also passes radially through the stem 12 andemerges at two substantially diametrically opposite points of the stem12, intersecting the axial channel 13 at the lower end of the valve stem12 so as to be in flow communication with the axial channel 13.

[0047] A closure element 15 is disposed inside the reservoir 2. Theclosure element 15 may be in the form of a base member, as shown,integrally formed with the valve stem 12 at the end of the valve stem 12disposed within the reservoir 2. The closure element 15 shown in FIG. 1includes a base member having a transverse wall of cross-sectional areaS₃ greater than the cross-sectional area S₂ of the valve stem 12. Theface of the base member turned away from the bottom 3 of the container 2forms a peripheral annular ring 16 defining a free edge which, under theaction of the pressure inside the container 2, presses with a sealingaction on a corresponding face 17 of the sealing member 8. The closureelement 15 according to this embodiment is shown in the perspective viewof FIG. 3. When the valve 7 is closed, the radial channel 14communicates with an annular space bounded by the annular base membersurrounding the valve stem 12, the annular ring 16 and the sealingmember 8, but is closed from flow communication with the product in thereservoir.

[0048] Force-fitted on the valve stem 12 at the opposite end from theclosure element 15 is a pushbutton 20 containing a passage 21 leading toa nozzle 22. The nozzle 22 defines an outlet 23 of the dispenser. Thepushbutton 20 has a bearing surface 24, allowing the user to operate thevalve 7 and dispense the product held inside the container. In certainembodiments, both the pushbutton 20 and the valve 7 may be moldings of athermoplastic material, such as a polypropylene or a polyethylene, forexample.

[0049] In the closed position illustrated in FIG. 1, the pressure insidethe container acting on the cross-sectional area S₃ of the closureelement 15 causes the annular ring 16 to press with a sealing action onthe face 17 of the sealing member 8.

[0050] As illustrated in FIG. 2, a force exerted by a user (more or lessin the direction of the X axis) on the surface 24 of the pushbutton maybe sufficient to overcome the force acting on the cross-sectional areaS₃ due to the pressure inside the reservoir 2. The valve stem 12 istherefore depressed axially, breaking the seal formed by the annularring 16 and the sealing member 8. The product located in the vicinity ofthe valve 7 flows into the radial channel 14, along the axial channel 13of the valve stem, into the passage 21 of the pushbutton 20, and isdispensed through the outlet 23. To position the product in the vicinityof the valve 7 for dispensing, the dispenser may be inverted if thedispenser if the propellant is disposed within the reservoir 2 and thepropellant is lighter than the product. When the user releases the forceon the surface 24, the force differentials referred to earlier push theclosure element 15 axially toward the opening of the reservoir until theannular ring 16 again presses with a sealing action against the face 17of the sealing member 8.

[0051] The above embodiment is suitable both for operation of the valveby axial depression or by lateral tilting. The closure element 15illustrated in FIG. 4 differs from that discussed with reference to theabove embodiment in that the base member is formed by a plurality ofradially oriented legs 30, 31, 32 spaced out regularly around the bottomportion of the valve stem 12. The radial channel 14 is at such adistance from the lower end of the valve stem 12 that, when the valve 7is closed, the open end (or ends) of the radial channel 14 is level withthe inner edge 10 of the sealing member 8. In the absence of anactuation of the dispenser, the radial channel is kept level with theinner edge 10 of the sealing member 8 by the pressure inside thereservoir, which acts both on the cross-sectional area S₂ of end of thevalve stem 12 disposed within the reservoir and on the totalcross-sectional area of the legs 30, 31, 32. With this configuration,the dispenser is actuated to open the valve by axially depressing thevalve stem 12.

[0052] When a sufficient force is applied to the bearing surface 24 ofthe pushbutton 20, the radial channel 14 is no longer level with theedge 10 of the sealing member 8, and the product is distributed via theradial channel 14, the axial channel 13, the passage 21, and the outlet23. When the user releases the force on the surface 24 of the pushbutton20, the closure element returns to the closed position in the same wayas in the previous embodiment, that is, in response to forcedifferentials resulting from pressure differentials within thereservoir, and flow communication between the reservoir 2 and thechannels 14, 13, the passage 21, and the outlet 23 is prevented.

[0053] Preferably, the dispenser contains a cosmetic, pharmaceutical,dermo-pharmaceutical, personal hygiene, or hair care product. However,in its broadest aspects, the present invention could be used to storeand dispense many other types of flowable substances. Furthermore, sizesof various structural parts and materials used to make these parts areillustrative and exemplary only and one of ordinary skill in the artwould recognize that these materials and sizes can be changed to producedifferent effects or desired characteristics of the dispensing assembly.

[0054] It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure andmethodology of the present invention. Thus, it should be understood thatthe invention is not limited to the examples discussed in thespecification. Rather, the present invention is intended to covermodifications and variations.

What is claimed is:
 1. A dispenser for dispensing a product, comprising:a reservoir for containing a product under pressure, said reservoirdefining an opening; a sealing member positioned on the reservoir; and avalve mounted in the opening, said valve including a closure elementdisposed within the reservoir, said closure element being configured tomove between a closed position wherein the closure element engages thesealing member to prevent flow communication between an outlet of thedispenser and the reservoir and an open position wherein the outlet isin flow communication with the reservoir, wherein the closure element ismoved to the closed position substantially by pressure inside thereservoir and is moved to the open position in response to an actuationof the dispenser.
 2. The dispenser of claim 1, wherein the valveincludes a valve stem and the closure element is integral with the valvestem.
 3. The dispenser of claim 2, wherein the closure element isintegral only with the valve stem.
 4. The dispenser of claim 2, whereinthe valve stem is slidably disposed within a passage defined by thesealing member.
 5. The dispenser of claim 4, wherein the valve stem isslidably disposed within the passage in a leaktight manner.
 6. Thedispenser of claim 4, wherein at least a portion of the sealing memberdefining the passage includes a coating to facilitate the sliding of thevalve stem through the passage.
 7. The dispenser of claim 6, wherein thecoating is silicone.
 8. The dispenser of claim 2, wherein the valve stemdefines at least one axial channel configured for flowing a producttherethrough.
 9. The dispenser of claim 8, wherein the axial channel isin flow communication with the outlet of the dispenser.
 10. Thedispenser of claim 8, wherein the valve stem further defines at leastone radial channel in flow communication with the at least one axialchannel.
 11. The dispenser of claim 10, wherein the radial channel isplaced in flow communication with the reservoir when the closure elementis in the open position.
 12. The dispenser of claim 10, wherein thevalve stem is slidably disposed within a passage defined by the sealingmember, the sealing member sealing the radial channel from flowcommunication with the reservoir when the closure element is in theclosed position.
 13. The dispenser of claim 12, wherein the radialchannel moves axially relative to the sealing member, placing the radialchannel in flow communication with the reservoir when the closureelement is in the open position.
 14. The dispenser of claim 2, whereinthe valve stem is configured to be one of depressed axially and tiltedin response to the actuation of the dispenser.
 15. The dispenser ofclaim 14, wherein the valve stem is configured to be depressed axiallyand the valve stem comprises a stop mechanism configured to limit axialmovement of the valve stem toward a bottom of the dispenser.
 16. Thedispenser of claim 10, wherein the closure element includes a basemember extending around a bottom portion of the valve stem.
 17. Thedispenser of claim 16, wherein the base member is in the form of anannulus having an annular ring extending vertically from the edge of theannulus toward the opening of the reservoir.
 18. The dispenser of claim17, wherein the annular ring engages with the sealing member when theclosure element is in the closed position, preventing flow communicationbetween the outlet and the reservoir.
 19. The dispenser of claim 18,wherein at least a portion of the annular ring disengages with thesealing member when the closure element is in the open position,allowing flow communication between the outlet and the reservoir. 20.The dispenser of claim 19, wherein the valve is configured to be one oftilted and depressed axially for actuating the dispenser and disengagingthe annular ring of the closure element from the sealing member.
 21. Thedispenser of claim 17, wherein the radial channel opens into an annularzone bounded by the annular ring and the annulus.
 22. The dispenser ofclaim 1, further comprising an actuating mechanism for moving theclosure element to the open position.
 23. The dispenser of claim 22,wherein the actuating mechanism includes a push-button mounted on avalve stem of the valve.
 24. The dispenser of claim 23, wherein thepushbutton defines the outlet of the dispenser.
 25. The dispenser ofclaim 1, wherein the reservoir contains a cosmetic product and apressurized propellant.
 26. The dispenser of claim 25, wherein thecosmetic product is chosen from a hair care product, a personal hygieneproduct, and a make-up product.
 27. A dispenser for dispensing aproduct, comprising: a reservoir configured to contain a product underpressure; and a valve mounted on the reservoir, said valve having avalve stem and a closure element disposed within the reservoir andintegrally formed with the valve stem, said closure element beingconfigured to be moved between a closed position wherein flowcommunication between an outlet of the dispenser and the reservoir isprevented and an open position wherein the outlet is in flowcommunication with the reservoir, wherein the valve is configured suchthat the closure element is moved to the closed position substantiallyby the pressure in the reservoir.
 28. The dispenser of claim 27, whereinthe valve stem defines at least one channel in flow communication withthe reservoir when the closure element is in the open position.
 29. Thedispenser of claim 27, further comprising a sealing member disposed inan upper portion of the reservoir.
 30. The dispenser of claim 29,wherein the sealing member defines a passage in which the valve stem isslidably disposed.
 31. The dispenser of claim 27, wherein the valve stemdefines at least one axial channel configured to allow a flow of producttherethrough.
 32. The dispenser of claim 31, wherein the valve stemdefines at least one radial channel in flow communication with the axialchannel.
 33. The dispenser of claim 32, wherein the radial channel is inflow communication with the reservoir when the closure element is in theopen position.
 34. The dispenser of claim 27, wherein the closureelement includes an annulus surrounding a bottom portion of the valvestem.
 35. The dispenser of claim 34, wherein an annular ring extendsvertically from the edge of the annulus toward a top of the dispenser.36. The dispenser of claim 35, wherein the annular ring engages with asealing member disposed in a top portion of the reservoir when theclosure element is in the closed position.
 37. The dispenser of claim36, wherein the valve stem includes a radial channel, the radial channelopening into an annular zone defined by the annulus and the annularring.
 38. The dispenser of claim 36, wherein at least a portion of theannular ring disengages with the sealing member when the closure elementis in the open position.
 39. The dispenser of claim 27, wherein thevalve stem is configured to be one of axially depressed and tilted formoving the closure member to the open position.
 40. The dispenser ofclaim 27, wherein the closure element includes a plurality of radiallyextending leg members disposed around a bottom portion of the valvestem.
 41. The dispenser of claim 40, wherein the valve stem defines aradial channel in a bottom portion of the valve stem.
 42. The dispenserof claim 41, wherein the radial channel is in flow communication withthe reservoir when the closure element is in the open position.
 43. Thedispenser of claim 42, wherein the radial channel is sealed from flowcommunication with the reservoir by a sealing member when the closureelement is in the closed position.
 44. The dispenser of claim 43,wherein the sealing member defines a passage in which the valve stem isslidably disposed.
 45. The dispenser of claim 44, wherein the valve stemis configured to be axially depressed for moving the closure element tothe open position.
 46. The dispenser of claim 45, wherein the radialchannel is displaced axially relative to the sealing member when thevalve stem is axially depressed.
 47. The dispenser of claim 27, whereinthe closure element is configured to be inscribed in a circle having across-sectional surface area that is greater than a cross-sectional areaof the valve stem.
 48. The dispenser of claim 27, wherein the pressureinside the reservoir decreases from a bottom of the reservoir toward theopening of the reservoir when the dispenser is in an upright position.49. The dispenser of claim 27, further comprising an actuating mechanismfor moving the closure element to the open position.
 50. The dispenserof claim 49, wherein the actuating mechanism comprises a push-buttonmounted on the valve stem.
 51. The dispenser of claim 50, wherein thepush-button is configured to be axially depressed.
 52. The dispenser ofclaim 50, wherein the push-button defines the outlet of the dispenser.53. The dispenser of claim 27, wherein the closure element includes afirst face facing a bottom of the reservoir and a second face facing atop of the reservoir, the pressure at the first face being greater thanthe pressure at the second face.
 54. The dispenser of claim 27, whereinthe pressure moving the closure element to the closed position includesa pressure acting on a face of the closure element facing the bottom ofthe reservoir and a pressure acting on an end of the valve stem disposedwithin the reservoir.
 55. The dispenser of claim 27, wherein thepressure within the reservoir is greater than atmospheric pressure. 56.The dispenser of claim 27, wherein the pressure within the reservoirmoving the closure element to the closed position exceedscounterbalancing forces acting on the closure element.
 57. The dispenserof claim 56, wherein the counterbalancing forces include the weight ofvarious structural components of the dispenser.
 58. The dispenser ofclaim 27, wherein the reservoir contains a cosmetic product and apropellant.
 59. The dispenser of claim 58, wherein the cosmetic productis chosen from a hair care product, a make-up product, and a personalhygiene product.
 60. The dispenser of claim 27, wherein the reservoirdefines an opening in a top portion of the reservoir and the valve ismounted in the opening.
 61. A dispenser for dispensing a product,comprising: a reservoir for containing a product under pressure; and avalve mounted on the reservoir, said valve having a valve stem and aclosure element disposed within the reservoir and fixed to the valvestem so as to prevent relative motion between the closure element andthe valve stem, said closure element being configured to move between aclosed position wherein flow communication between an outlet of thedispenser and the reservoir is prevented and an open position whereinthe outlet is in flow communication with the reservoir, wherein thevalve is configured such that the closure element is moved to the closedposition substantially by the pressure in the reservoir.
 62. Thedispenser of claim 61, wherein the valve stem defines at least onechannel in flow communication with the reservoir when the closureelement is in the open position.
 63. The dispenser of claim 61, furthercomprising a sealing member disposed in an upper portion of thereservoir.
 64. The dispenser of claim 63, wherein the sealing memberdefines a passage in which the valve stem is slidably disposed.
 65. Thedispenser of claim 61, wherein the valve stem defines at least one axialchannel configured to allow a flow of product therethrough.
 66. Thedispenser of claim 65, wherein the axial channel is in flowcommunication with the outlet of the dispenser.
 67. The dispenser ofclaim 66, wherein the valve stem defines at least one radial channel inflow communication with the axial channel.
 68. The dispenser of claim67, wherein the radial channel is in flow communication with thereservoir when the closure element is in the open position.
 69. Thedispenser of claim 61, wherein the closure element includes an annulussurrounding a bottom portion of the valve stem.
 70. The dispenser ofclaim 69, wherein an annular ring extends vertically from an edge of theannulus toward a top of the dispenser.
 71. The dispenser of claim 70,wherein the annular ring engages with a sealing member when the closureelement is in the closed position.
 72. The dispenser of claim 71,wherein the valve stem includes a radial channel which opens into anannular zone defined by the annulus and the annular ring.
 73. Thedispenser of claim 71, wherein at least a portion of the annular ringdisengages with the sealing member when the closure element is in theopen position.
 74. The dispenser of claim 61, wherein the valve stem isconfigured to be one of axially depressed and tilted for moving theclosure member to the open position.
 75. The dispenser of claim 61,wherein the closure element includes a plurality of radially extendingleg members disposed around a bottom portion of the valve stem.
 76. Thedispenser of claim 75, wherein the valve stem defines a radial channelin a bottom portion of the valve stem.
 77. The dispenser of claim 76,wherein the radial channel is in from flow communication with thereservoir when the closure element is in the open position.
 78. Thedispenser of claim 77, wherein the radial channel is sealed from flowcommunication with the reservoir by a sealing member when the closureelement is in the closed position.
 79. The dispenser of claim 78,wherein the sealing member defines a passage in which the valve stem isslidably disposed.
 80. The dispenser of claim 79, wherein the valve stemis configured to be axially depressed for moving the closure element tothe open position.
 81. The dispenser of claim 80, wherein the radialchannel is displaced axially relative to the sealing member when thevalve stem is axially depressed.
 82. The dispenser of claim 61, whereinthe closure element is configured to be inscribed in a circle having across-sectional surface area that is greater than a cross-sectional areaof the valve stem.
 83. The dispenser of claim 61, wherein the pressureinside the reservoir decreases from a bottom of the reservoir toward atop of the reservoir when the dispenser is in an upright position. 84.The dispenser of claim 61, further comprising an actuating mechanism formoving the closure element to the open position.
 85. The dispenser ofclaim 84, wherein the actuating mechanism comprises a push-buttonmounted on the valve stem.
 86. The dispenser of claim 85, wherein thepush-button is configured to be axially depressed.
 87. The dispenser ofclaim 61, wherein the closure element includes a first face facing abottom of the reservoir and a second face facing a top of the reservoir,the pressure on the first face being greater than the pressure on thesecond face.
 88. The dispenser of claim 61, wherein the pressure movingthe closure element to the closed position includes a pressure acting ona face of the closure element facing a bottom of the reservoir and apressure acting on an end of the valve stem disposed within thereservoir.
 89. The dispenser of claim 61, wherein the pressure withinthe reservoir is greater than atmospheric pressure.
 90. The dispenser ofclaim 61, wherein the pressure within the reservoir moving the closureelement to the closed position exceeds counterbalancing forces acting onthe closure element.
 91. The dispenser of claim 90, wherein thecounterbalancing forces include the weight of various structuralcomponents of the dispenser.
 92. The dispenser of claim 61, wherein thereservoir contains a cosmetic product and a propellant.
 93. Thedispenser of claim 92, wherein the cosmetic product is chosen from ahair care product, a make-up product, and a personal hygiene product.94. The dispenser of claim 61, wherein the reservoir defines an openingin a top portion of the reservoir and the valve is mounted in theopening.
 95. A method of dispensing a product, comprising: providing thedispenser of claim 1; actuating the dispenser to move the closureelement to the open position; dispensing a product under pressure fromthe dispenser in response to the actuating; ceasing the actuating; andmoving the closure element to the closed position substantially by thepressure in the reservoir.
 96. The method of claim 95, wherein thepressure contributes by more than approximately 50 percent to the movingof the closure element to the closed position.
 97. The method of claim95, wherein the pressure contributes by more than approximately 75percent to the moving of the closure element to the closed position. 98.The method of claim 95, wherein the pressure contributes by more thanapproximately 90 percent to the moving of the closure element to theclosed position.
 99. The method of claim 95, wherein the pressure in thereservoir is greater than atmospheric pressure.
 100. The method of claim95, wherein the pressure within the reservoir at a first face of theclosure element facing a bottom of the reservoir is greater than thepressure at a second face of the closure element facing a top of thereservoir.
 101. The method of claim 95, wherein the moving the closureelement to the closed position includes moving the closure element bythe pressure on a face of the closure element facing a bottom of thereservoir.
 102. The method of claim 95, wherein the actuating includesone of axially depressing and tilting a valve stem of the valve. 103.The method of claim 102, wherein the one of axially depressing andtilting the valve stem causes immediate movement of the closure elementto the open position.
 104. The method of claim 95, wherein the actuatingincludes inverting the dispenser.
 105. The method of claim 95, whereinthe dispensing includes flowing the product through the outlet of thedispenser.
 106. The method of claim 105, wherein the dispensing furtherincludes flowing the product through at least one channel defined by thevalve, the channel being in flow communication with the outlet.
 107. Themethod of claim 95, wherein the dispensing the product includesdispensing a cosmetic product and a pressurized propellant.
 108. Themethod of claim 107, wherein the cosmetic product is chosen from a haircare product, a personal hygiene product, and a make-up product. 109.The method of claim 95, further comprising engaging the closure elementwith the sealing member.
 110. A method of dispensing a product,comprising: providing the dispenser of claim 27; actuating the dispenserto move the closure element to the open position; dispensing a productunder pressure from the dispenser in response to the actuating; ceasingthe actuating; and moving the closure element to the closed positionsubstantially by the pressure in the reservoir.
 111. The method of claim110, wherein the pressure contributes by more than approximately 50percent to the moving of the closure element to the closed position.112. The method of claim 110, wherein the pressure contributes by morethan approximately 75 percent to the moving of the closure element tothe closed position.
 113. The method of claim 110, wherein the pressurecontributes by more than approximately 90 percent to the moving of theclosure element to the closed position.
 114. The method of claim 110,wherein the pressure in the reservoir is greater than atmosphericpressure.
 115. The method of claim 110, wherein the pressure within thereservoir at a first face of the closure element facing a bottom of thereservoir is greater than the pressure at a second face of the closureelement facing a top of the reservoir.
 116. The method of claim 110,wherein the moving the closure element to the closed position includesmoving the closure element by the pressure on a face of the closureelement facing a bottom of the reservoir and by the pressure on an endof the valve stem disposed within the reservoir.
 117. The method ofclaim 110, wherein the actuating includes one of axially depressing andtilting the valve stem.
 118. The method of claim 117, wherein the one ofaxially depressing and tilting the valve stem causes immediate movementof the closure element to the open position.
 119. The method of claim110, wherein the actuating includes inverting the dispenser.
 120. Themethod of claim 110, wherein the dispensing includes flowing the productthrough the outlet of the dispenser.
 121. The method of claim 120,wherein the dispensing further includes flowing the product through atleast one channel defined by the valve stem, the channel being in flowcommunication with the outlet.
 122. The method of claim 110, wherein thedispensing the product includes dispensing a cosmetic product and apressurized propellant.
 123. The method of claim 122, wherein thecosmetic product is chosen from a hair care product, a personal hygieneproduct, and a make-up product.
 124. The method of claim 110, furthercomprising engaging the closure element with a sealing member.
 125. Amethod of dispensing a product, comprising: providing the dispenser ofclaim 61; actuating the dispenser to move the closure element to theopen position; dispensing a product under pressure from the dispenser inresponse to the actuating; ceasing the actuating; and moving the closureelement to the closed position substantially by the pressure in thereservoir.
 126. The method of claim 125, wherein the pressurecontributes by more than approximately 50 percent to the moving of theclosure element to the closed position.
 127. The method of claim 125,wherein the pressure contributes by more than approximately 75 percentto the moving of the closure element to the closed position.
 128. Themethod of claim 125, wherein the pressure contributes by more thanapproximately 90 percent to the moving of the closure element to theclosed position.
 129. The method of claim 125, wherein the pressure inthe reservoir is greater than atmospheric pressure.
 130. The method ofclaim 125, wherein the pressure within the reservoir at a first face ofthe closure element facing a bottom of the reservoir is greater than thepressure at a second face of the closure element facing a top of thereservoir.
 131. The method of claim 125, wherein the moving the closureelement to the closed position includes moving the closure element bythe pressure acting on a face of the closure element facing a bottom ofthe reservoir and by the pressure acting on an end of the valve stemdisposed within the reservoir.
 132. The method of claim 125, wherein theactuating includes one of axially depressing and tilting the valve stem.133. The method of claim 132, wherein the one of axially depressing andtilting the valve stem causes immediate movement of the closure elementto the open position.
 134. The method of claim 125, wherein theactuating includes inverting the dispenser.
 135. The method of claim125, wherein the dispensing includes flowing the product through theoutlet of the dispenser.
 136. The method of claim 135, wherein thedispensing further includes flowing the product through at least onechannel defined by the valve stem, the channel being in flowcommunication with the outlet.
 137. The method of claim 125, wherein thedispensing the product includes dispensing a cosmetic product and apressurized propellant.
 138. The method of claim 137, wherein thecosmetic product is chosen from a hair care product, a personal hygieneproduct, and a make-up product.
 139. The method of claim 125, furthercomprising engaging the closure element with a sealing member.